OVA

OVA (オーブイエー / オーヴィーエー / オヴァ) (short for Original video animation) are animated films and series made specially for release in home-video formats. Most OVAs are released to direct-to-video, without showings on television or in theaters. Most OVA's are commonly mistaken to just be a short anime series, due to most OVA episodes being very short (usually around a few minutes) but some episodes can be up to a couple of hours.